This paper proposes that different experimental contexts (single or dual language contexts) permit different neural loci at which words in the target language can be selected. However, in order to develop a fuller understanding of the neural circuit mediating language control we need to consider the community context in which bilingual speakers typically use their two languages (the behavioural ecology of bilingual speakers). The contrast between speakers from code-switching and non-code switching communities offers a way to increase our understanding of (...) the cortical, subcortical and, in particular, cerebellar structures involved in language control. It will also help us identify the non-verbal behavioural correlates associated with these control processes. (shrink)

This paper develops the view that in arguing informally individuals construct a dual representation in which there is a coupling of arguments and the structure of the qualitative (mental) causal model to which these refer. Invited to consider a future possibility, individuals generate a causal model and mentally simulate the consequences of certain actions. Their arguments refer to the causal paths in the model. Correspondingly, faced with specific arguments about a policy option they generate a model with particular causal paths (...) and mentally simulate the outcomes. The results of Experiment 1 are consistent with this notion. Decisions on the percentage of funds to be allocated to genetically modified (GM) crop research depended on the structure of the arguments elicited in response to imagining a future state of affairs. Specifically, the presence of a dissuasive argument eliminated the impact of any persuasive argument. The non-monotonic properties of everyday informal argument can then be seen as a corollary of change to causal structure in the model. The dual representation view predicts that the impact of a dissuasive argument will depend on the structure of the causal model. Experiment 2 tested and confirmed this prediction by requiring individuals to judge the relative persuasiveness of two cases referring either to a model with two independent causal paths or to a model in which one causal path depended on the other. In contrast to Experiment 1, prior opinion on GM crop research did not affect allocation decisions. An advisory role in contrast to a participant role may encourage a more decontextualised mode of thinking. According to the dual representation view, ease of mental simulation should exert wide-ranging effects on judgements and the rhetoric of arguments should also be important. The paper concludes with a discussion of some of these expectations. (shrink)

We examine how opinion on a controversial real-world issue shifts as a function of reading relevant arguments and engaging in a specific mental simulation about a future, fictional state of affairs involving the target issue. Individuals thought either counterfactually about a future event (“if only X had not happened …”) or semifactually about it (“even if X had not happened …”). In Experiment 1, as expected, individuals became more in favour of a course of action (the electronic tagging of children) (...) after reading relevant supporting arguments. They also became more in favour after they thought counterfactually how a negative future event could have been avoided if only electronic tagging had not been banned some years earlier. The effects of argument relevance and type of mental simulation were additive. Using a similar procedure but a different target issue (whether the UK should join the Economic Monetary Union), Experiment 2 confirmed that the type of mental simulation exerts a substantial effect on the impact of relevant arguments. Much weaker effects arose when the mental simulation was not relevant to the target issue. We set and discuss our results in terms of dual-processing theory. (shrink)

Two experiments, using a mock legal case, confirmed the causal role of arguments in verdict decisions and explored the process involved. Experiment 1 showed that verdicts varied with the strength of counter-arguments and Experiment 2 showed that the use of background information that undermined such arguments determined the verdict reached. Such results confirm the causal role of arguments but do not speak to the representations constructed. In both experiments we analysed the reasons proposed for verdicts. Participants generally represented the state (...) of affairs, and conjectured state of affairs, to which the arguments referred. Experiment 2 also asked participants about the number of causal possibilities they envisaged. Confidence in the verdict was moderated by the strength of counter-arguments but in different ways for those who envisaged a single causal account as opposed to two causal accounts. In the former case, confidence decreased with the rated strength of counter-arguments. In the latter case, confidence increased. We suggest that verdicts are abductive explanations of the events generated through a process of mental simulation. (shrink)

Hardman in press claims that the results of Green and Larking 1995 favour a mental rules theory account of performance in the selection task over a mental model theory account. This reply rebuts his claim.

Abstract In order to be a general theory of human cognition, the theory of mental models needs to accommodate a variety of forms of reasoning in addition to deduction. The mental model theory of induction is a crucial step in establishing generality. After suggesting that the theory of mental models can also account for abduction and analogy, the paper points out that inductive performance is likely to be constrained both by the nature of the representation used and by strategic factors. (...) Since human cognition involves the communication of arguments, a final section explores the relationship between the theory of mental models and the notion of an argument. It proposes that models can contain tokens of inductive arguments which can be referred to in the course of other arguments. (shrink)